IIRC they were wired directly to the XLR master outputs which is not a good idea because this introduces distortion from the meters into the outputs. But it´s too long ago that I opened a Scorpion with originally fitted meters to remember any details....I did add meters to a Scorpion a few years ago by using a JLM audio meter buffer between meters and outputs. See here: https://www.jlmaudio.com/shop/vu-buffer-kit.htmlYou can easily get the necessary supply voltage for the buffers from the LED-meter PCB, just a few inches away from the VUs.